Unveiling kaempferol glycosides as the key antiglycative components in butterfly pea (Clitoria ternatea) flower

Edible flowers have been used in dietary practices since ancient times. In recent years, they have garnered increasingly more attentions for their potentials in the prevention and amelioration of pathological conditions. The present study employed in vitro BSA models to evaluate the antiglycative effect of some edible flowers. Results showed that butterfly pea flower (BFPF) exhibited the highest potential in preventing advanced glycation end products (AGEs) formation, which had an inhibition rate of 92.11% at 1 g/mL, 56.99% at 0.1 g/mL, and 9.94% at 0.01 g/mL, respectively. Moreover, the antiglycative components in BFPF were identified as four flavonol glycosides through chromatographic and spectral analyses, which were manghaslin (quercetin 3-2″-rhamnosylrutinoside, QCT-Rh), clitorin (kaempferol 3-2″-rhamnosylrutinoside, KFR-Rh), rutin (quercetin 3-rutinoside), and kaempferol 3-neohesperidoside (KFR-Ne). Notably, KFR-Rh and KFR-Ne were presented in higher concentrations in BFPF (764.31 mg/kg and 1135.10 mg/kg dry matter) and significantly contributed to the antiglycative activity (IC₅₀ = 182.17 μM and IC₅₀ = 131.03 μM). Molecular docking (MD) and nuclear magnetic resonance (NMR) analyses revealed that KFR-Rh and KFR-Ne formed hydrogen bonds and hydrophobic interactions with BSA, while KFR-Ne demonstrating a stronger interaction than KFR-Rh. Collectively, our findings highlight the beneficial effects of BFPF with clearly identified active components, which might further promote its application in functional food and medical industry.